What Killed the Mega Beasts?: For 65 million years, fantastic creatures roamed the prehistoric world. At the end of the last Ice Age, hundreds of species disappeared. Find out what caused the demise of the 17-foot-tall sloths, the woolly mammoths, and the Australian marsupial lion.Prehistoric Assassins: Millions of years ago, the earth'soceans were home to some of the fiercest creatures to ever roam the planet, including a giant bone-jawed beast and a six-foot sea scorpion. Although long extinct, their prehistoric weapons can still be found today.Rise of the Feathered Dragon: Follow the work of paleontologists in remote northwestern China as they search for fossil evidence to the origins of modern birds.